The field of this invention relates to weight determining devices and more particularly to a weight determining device which does not require the use of any separate weighing device in order to ascertain the weight of a given structure.
The subject matter of this invention will be discussed in conjunction with motor vehicles and more particularly in conjunction with trucks. However, it is to be understood that it is within the scope of this invention that the weight could be utilized in environments other than motor operated vehicles and actually within any environment where it is desired to determine the weight of an object without the using of any separate scale mechanism.
Trash trucks are designed to move from house to house, or business to business, and collect accumulated trash which has been placed in an appropriate collecting container to be picked up by the individuals operating the trash trucks. Trash trucks are normally required by municipalities, which generally is a city or a county, to restrict its weight to no greater than a certain value. Since the individuals operating the trash truck are constantly picking up additional weight, it is merely guesswork by the operators of the trash truck as to how much weight has actually been accumulated. This guesswork frequently results in the truck being overweight. Most municipalities are quite diligent in determining which trucks are overweight and if they are overweight a fine is assessed. Generally, these fines are based on the amount of pounds that the truck is overweight. It is not at all uncommon for an overweight truck to receive a fine of several thousand dollars.
A business which operates a plurality of trash trucks may have to pay fines of several thousand dollars in a given month. These fines are actually totally unnecessary and if there was some convenient and quick way the trash truck operator could discover the weight of the truck, the trash truck operator could then stop adding additional trash when the truck weight was at its maximum and then proceed to the dumping facility for the trash so that the truck could be emptied. The truck could then be operated back to its place where the truck stopped picking up the trash and the truck could then continue on its route.
Previously, it has been known to incorporate some type of weighing device in conjunction with the truck. However, all previous type of such weighing devices involve the use of a strain gauge. The strain gauge is mounted on a load bearing member such as an axle of the truck. The strain gauge is to be placed at the center of the bending moment of the axle, in other words, the point on the axle which flexes the greatest. The problem with strain gauges is that they encounter fatigue. The constant bending and non-bending movement of the axle results in the deterioration of the strain gauge. As a result, the strain gauge frequently breaks or otherwise become inoperative. Prior to becoming inoperative, the strain gauge will result in substantially inaccurate weight readings. The weight calculated by the strain gauge would appear to not have the truck overloaded when in fact the truck would be overloaded.
Another way in which trucks can be weighed without placing the truck on a scale is through the use of a load cell. However, such load cells are required to be installed within some point of the vehicle which will encounter the weight of the load on the truck. These load cells require that the truck be somewhat dismantled so the load cell can be installed. Load cells also have the problem that they deteriorate over time and become inaccurate. These load cells are continuously subjected to the weight of the load and also to variations of this as the truck is vibrated during normal operation. It is this constant subjecting to load and the varying of the load weight that results in deterioration of the load cell.
Prior to the development of the structure of the present invention, there has not been known any type of load weighing device that could be quickly and easily mounted on the structure of the truck without requiring any dismantling of the truck and that operated reasonably accurate over a long period of time without deterioration and also was unaffected by typically encountered weather conditions such as rain, cold, heat, snow and mud.